The invention relates to connector assemblies for electronic devices; and, more particularly, to component assemblies and processes for manufacturing implantable device connectors.
Implantable medical devices (IMDs), such as implantable cardioverter/defibrillators (ICDs) and pacemaker/cardioverter/defibrillators (PCDs), can detect and administer therapy for a variety of cardiac conditions. These conditions include ventricular fibrillation (VF), atrial fibrillation (AF), tachycardia, and bradycardia. IMDs typically include a housing that encloses a variety of internal components and isolates them from the implanted environment. Within the human body, for example, the housing must be sealed to prevent ingress of fluids which can cause the device to short circuit or corrode internal components, rending the IMD inoperable.
In many IMDs, integrated circuits, batteries, and other components are enclosed in hermetically sealed metallic enclosures known as xe2x80x9ccans.xe2x80x9d In many systems, components within the IMD can are coupled electrically to components such as medical leads that are outside of the case. For example, one or more medical leads may be coupled to a connector module affixed to the outside of the can. The electrical connections between the connector module and the inside of the can are generally made by conductors extending between the connector and the IMD components.
By way of example, an ICD includes an internal battery, a charging capacitor, and electronic circuitry. The electronic circuitry is ordinarily coupled to pacing and diagnostic leads that are attached to a connector outside of the device housing for positioning within or near the heart. To protect internal components while permitting electrical connections with external components, the ICD includes a feedthrough assembly that preserves the environmental integrity of the device housing. The feedthrough assembly supports feedthrough pins that extend through the hermetically sealed can. These feedthrough pins are coupled to conductors such as wires. In prior art designs, these wires may be threaded through feedthrough apertures in the connector module. Then the wires are routed along an outside surface of a connector module so that they can be electrically coupled via a welding or soldering process to a respective connector block of the connector module.
Problems exist with the above-described manufacturing method. First, because the wires from the device must extend to a respective connector block of the connector assembly, the device wires must be relatively long. As a result, it is cumbersome to insert the device wires through the feedthrough of the connector block, and to then route the wires over the connector block surface.
Another problem with the prior art mechanism involves the use of jumper wires. If the original device wires are not long enough to extend to the desired connector block, jumper wires must be welded to the end of the wire to extend the length. Generally, this process involves a wire-to-wire, cross-welding process. This cross-welding is time-consuming and difficult. Moreover, the weld joints may exhibit undesirable mechanical and structural stresses that may affect the reliability, operation, and maintainability of the medical device. Finally, the weld joints have a tendency to buckle, which may cause a breach in the insulative adhesive material that is generally applied over the conductors to protect them from bodily fluids, leading to short circuits or other possible device failures.
Yet another problem associated with the above process involves the inability to ready the connector module for assembly on the device. Because the device wires are used as the conductors that couple the connector blocks with the internal device components, none of the welds may be completed prior to affixing the connector module to the can. As a result, much of the assembly work is performed in the last stages of device production, reducing the amount of parallelism that can be achieved during device assembly, and increasing the overall length of the assembly process. Additionally, performing the welding processes after the device is affixed to the connector is more cumbersome, increasing the complexity of the process.
Manufacturability is a significant concern in the design of implantable medical devices. As a result, efforts to simplify or reduce the complexity, cost, and time of the manufacturing process can directly impact the cost of the implantable medical device for patients. Accordingly, a more simple and cost-effective manufacturing process for use in the assembly of connector modules is needed.
The invention is generally directed to interconnecting schemes for improved assembly of electronic devices, and implantable medical devices in particular. More specifically, a connector module incorporates internal weld plates that eliminate the need for extended-length device wires and cross-wire welds. As a result, the manufacturing process is greatly simplified, decreasing the unit cost of production.
One particular embodiment of the invention involves a device including at least one electrical component enclosed within a housing. The electrical component is electrically coupled to a device conductor such as a wire that extends outside of the housing. A connector assembly is positioned proximal the device, and may be affixed to the device with an adhesive and/or a fastening member. The connector assembly includes at least one connector block, such as may be adapted to mechanically and electrically couple to an electrical lead, although any other type of mechanism for making an electrical contact may be used as a connector block. The connector assembly further includes at least one weld plate. A conductor such as a wire is routed between the connector block and the weld plate and electrically coupled to both structures. The weld plate is further electrically coupled to the device conductor such that the electrical component is electrically coupled to the connector block.
According to one aspect of the invention, the connector assembly may include recessed channels such as wireways to maintain the conductors in a predetermined position along a surface of the connector assembly. At least a portion of one surface of the connector assembly may further be provided with an insulative layer such as an adhesive. This adhesive may be applied over one or more of the conductors, for example, to maintain the position of these components and provide an insulative, protective layer. The entire connector assembly may be coated with a material of this nature, if desired.
One example of the invention may be provided by an implantable medical device (IMD). The can of the IMD houses electronic circuitry. One or more device conductors coupled to the circuitry extend outside of the can. Affixed to the can is a connector assembly, which may include one or more connector blocks adapted to receive a respective connector member of a medical electrical lead. The connector assembly further includes one or more weld plates that may be molded within, or otherwise affixed, to a surface of the connector assembly. A conductor such as a wire extends between a given connector block and a weld plate, and is electrically coupled to each. A device conductor is further electrically coupled to a weld plate such that an electrical connection is made between the electronic circuitry and a given connector block.
Another embodiment is directed to a method of manufacturing an IMD system. An implantable medical device and a connector assembly are provided. The connector assembly includes at least one connector block and at least one weld plate. A conductor is arranged proximal to the connector assembly for electrically coupling a connector block with a weld plate. The connector assembly is then mounted to the IMD, and a device conductor extending from within the IMD is electrically coupled to the weld plate.
The system and method of the current invention simplifies the manufacturing of electronic devices such as IMDs by allowing most of the conductive traces to be attached prior to the coupling of the connector assembly with the device. This increases the parallelism possible in the manufacturing process. Additionally, the use of the weld plates allows the device conductors to be much shorter, since they do not need to extend directly to the connector blocks. This makes the assembly process less cumbersome. Moreover, the cross-weld interconnections formerly employed to couple jumper wires to the device conductors to extend their length may be eliminated. This eliminates a potential source of failure, as well as a time-consuming step in the assembly process. Finally, mechanical performance and reliability is also improved because of the reduced mechanical and structural stresses associated with the longer device conductors.
The above summary of the invention is not intended to describe every embodiment of the invention. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.